Question 305479
5x^2-16x-84=0
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
x=(16+-sqrt[16^2-4*5*-84])/2*5
x=(16+-sqrt[256+1,680])/10
x=(16+-sqrt[1,936)/10
x=(16+-44)/10
x=(16+44)/10
x=60/10
x=6 ans.
x=(16-44)/10
x=-28/10
x=2.8 ans.